Feeding a Booming Population Without Destroying the Planet

By WILLIAM K. STEVENS

Published: April 5, 1994

AS modern contraceptives steadily reduce birth rates in the third world, the surging wave of humans now engulfing the earth is expected to level off in a century or so. But by then the global population is likely to have doubled, and this grim realization is reshaping efforts to address the planet's overriding ecological question:

Will all those people -- nearly 12 billion of them -- be able to provide decent lives for themselves without doing irreversible damage to the croplands, water resources, forests, fisheries and other ecological resources on which life ultimately depends?

The question is central to discussions at a preparatory conference on population policy that opened yesterday at the United Nations and will continue over the next three weeks. The delegates hope to develop a plan for action on population that would be adopted in its final form next September at the International Conference on Population and Development in Cairo.

The debate on population and resources historically has divided neatly into two camps. Neo-Malthusians, principally ecologists and biologists, predicted general disaster unless the population surge was contained. Cornucopians, mainly economists, argued conversely that as scarcity develops, it will surely be defeated by human inventiveness in raising crop yields and coping with diminishing resources.

These arguments have now been joined by a third view which holds that products of human ingenuity like the science-based Green Revolution, in which the development of high-yield grains enabled food production to keep pace with the population explosion of the last quarter-century, do indeed hold the key to supporting an expanding populace.

But advocates of the third view argue that ingenuity of this sort does not materialize automatically; in the case of agriculture, experts say, it has been sputtering in recent years because of complacency and lack of support. And even if new solutions can be devised, they say, some countries will lack the social and political inventiveness to take timely advantage of them.

In the 21st century, according to one scholar, some countries will win the race between need and ingenuity, while others will fail and sink into varying degrees of poverty, violence and environmental degradation. These failures will touch off national and regional crises rather than a global one, says Dr. Thomas F. Homer-Dixon, a political scientist at the University of Toronto who is a foremost exponent of the third view.

He defines ingenuity as ideas applied to technical and social problems, and its supply, he says, can be blocked by a number of factors arising from a country's political and social institutions. These include, for instance, a lack of trained scientists and technologists, a shortage of research funds, institutional resistance to innovation and social conflict arising from scarcity.

"A persistent and serious ingenuity gap will cause major social changes, like declining food production, reduced economic production and large population movements," Dr. Homer-Dixon says in an unpublished paper, contending that these changes "will increase the likelihood of widespread and chronic civil violence." His paper grew out of a three-year study conducted under the auspices of the American Academy of Arts and Sciences and the Peace and Conflict Studies Program at the Toronto university. Birth Rates Are Dropping

The world population, now 5.7 billion, is double that of the late 1950's. More than three-quarters of those alive today live in developing countries, and more than half in Asia. Third world birth rates have been dropping since the 1960's. United Nations demographers expect them to reach the "replacement level" of a little more than two births per woman of child-bearing age in all countries no later than 2045, and much earlier than that in many. China's rate is now below replacement level; India's is expected to reach it between 2015 and 2020. The birth rate in industrialized countries is already slightly below replacement level.

Although birth rates are dropping, United Nations projections, which have proved quite accurate till now, show the world population reaching nearly 8.5 billion by 2025, with more than 7 billion living in what are now developing countries. The demographic momentum, even with slower growth, means the overall population will exceed 10 billion in 2050 and 11 billion in 2100, before stability finally sets in at 11.6 billion between 2150 and 2200.

Changes in expected fertility trends could alter the projections, and Larry Heligman, chief of the United Nations population projections group, said that the birth rate has recently declined for the first time in a number of Asian and African countries.

But he said that even if replacement level were magically achieved everywhere, the global population would still grow to 7.1 billion in 2025 and 8.1 billion by 2100, barring some unforeseen catastrophe.

The global projections understate the problem in the third world. According to the U.N., third world populations will nearly double in 30 years and increase by two and a half times before stabilizing. In some countries, a threefold or fourfold increase is expected.